Adjustable-electrode spark-plug.



D. M. CLARK. ADJUSTABLE ELECTRODE SPARKELUG. APPLICATION FILED MAY-7,I915, RENEWED NOV. 10. 1917.

1,256,201 Patented Feb.- 12, 1918.

witness/m n m: mmmasmklou o c one stationary electrode.

DANIEL M. CLARK, 0F JAMESBURG, NEW JERSEY.

ADJUSTABLE-ELECTRODE SPARK-PLUG.

Specification of Letters Patent.

Patented Feb. 12, 19.18.

Application filed May 7, 1915, Serial No. 26,622. Renewed November10,191). I Serial No. 201,408.

To all whom it may concern:

Be it known that I, DANIEL M. CLARK, a citizen of the United States,residing at J amesburg, in the county of Middlesex and State of NewJersey, have invented certain new and useful Improvements in Adjustable-Electrode Spark-Plugs, of which the following is a specification.

This invention relates to adjustable electrode sparkplugs, wherein thewidth of the spark gap may be varied, and has for its object theproduction of a jump spark plug comprising parts of special constructionand arrangement and having one movable and The movable electrode isarranged to be turned into a wiping contact with the stationaryelectrode whereby both are cleared of any carbon deposit. In addition,sparkplugs constructed in accordance with this invention are furnishedwith a handle provided with an indicator or pointer and attached to themovable or revoluble electrode so that when the handle is moved to turnthe electrode the indicator is correspondingly moved. A suitable scaleis arranged adjacently or upon the plug in position to be pointed to orswept by the indicator. Thus, the distance moved by the revolubleelectrode with relation to the stationary electrode, which distance isthe spark gap, may be pointed out upon the scale by the indicator. It isalso an object of this invention'to provide a number of sparkplugs eachhaving a movable and a stationary electrode, and to construct means foractuating all the movable electrodes and to indicatethe spark gap upon ascale supported near the handle. It is also an object of this inventionto produce means for releasably securing in any given positionthe partsemployed to move the movable electrodes, which may be accomplishedbyfixing the handle in its position through the agency of the deviceshereinafter specified, so that the adjustment of the electrodes beinonce made it'will not be changed under or inary serviceconditions untilfurther adjustment is deemed necessary.

The construction and arrangements of the parts of this invention areillustrated in the accompanying drawings'of which Figure 1 represents avertical section of the body portion and aside ,view of the other partsassembled. Fig. 2'is-a top plan view. Fig; 3

is a cross-section on the horizontal broken line w-w of Fig. 1. Fig. 4is a side view,

partly in vertical section, showing the means for operating the movableelectrodes of more than one sparkplug, with the devices for indicatingthe spark gap and for securing the members in position after they havebeen adjusted.

In the drawings, and throughout the description the same letter isusedto refer to the same part.

Considering the drawings, the sparkplug has the metallic body portion A,and a central stationary insulated electrode (1. There is provided arevoluble electrode B having at its lower end a conical gas checlrC, andthe electrode is rotatively movable in a passage 0 extending lengthwisethrough the wall of the body A. The lower end of the movable electrodeis marked D andit is bent as shown and constructed to be turned into awiping contact with the end of the stationary electrode, as best shownin Fig. .3.

The passage 0 as shown extends lengthwise through the wall of the body.A, which is the external metallic body. In all the sparkplugs of thischaracter with which this applicant is acquainted, the adjustableelectrode passes through theporcelain, and, the porcelain forms thecentral member of the I plug. It is necessary to hook or otherwiseconnect the conducting wire to the central electrode, and in therepeated adjustments, connecting and disconnecting the wire, and thenecessary movements of the movable electrode to keep the electrodes freefrom carbon deposits, the porcelain insulator; is especially likely tobe broken. By boring the .passage 0 through'the metallic wall of thebody A, the body is not materially weakened and cannot be broken by anyamount of rough handling. Furthermore, by passing the movable electrodethrough and in metallic contact with the body and, therefore, with theengine or ground, as that term is em ployed, the outer end. of themovable electrode is most conveniently placed for adjusting theelectrodes of several plugs together by a connection from the dash asdescribed herein.

An insulating handle E is secured to the movable electrode by means of anut 12, and the handle is provided with an indicator or pointer earranged above and intended to trode corresponds to the movement of themove over-the scale F that is secured externally upon the body portion.The handle is substantially horizontal and the scale is positionedaccordingly. As shown, the passage 0 in the wall of the body portion,and, consequently, the attitude of the electrode B vis necessarilyslightly inclined.

In Fig. 4, this invention is illustrated as comprising more than onesparkplug. The sparkplugs G- and g are connected by the posts H and'hwith a rack bar J having the toothed portion or rack j. The connectionsI are of like construction for each sparkplug.

Thus, the post H has a clamp h that engages the roundedend of the handleE. The handle E is in all respects similar in structure to the handle E,best shown in Fig. 2, and it is provided with an indicator such as theindicator 6, but not shown. The 20 scale F is alike in its form andarrangement with the-scale F. The movable electrode B of the sparkplug Gis secured to the handle E by means of the nut b. \Vhatever the numberof sparkplugs employed, they may each have the handle with the indicatoranl the scale, or the indicator and scale may be omitted upon eachsparkplug when there are a number of sparkplugs, and'the scale mem-.

' her and indicator may be otherwise disposed as explained below. 1

The rack bar H is caused to move back and forth by theengagement of therack j and the toothed sector K onthe transverse short shaft k, which ismounted in the bearingsL supported by the dashboard Z. A handle M,passing through and operating in a slot on in the board, has one of itsends connected with the shaft 70, and the other end is-provided with ahandpiece N that is threaded internally and engages the like threadedend a of the handle. The handle sweeps a scale P borne by the board, andan indicating arrowhead Q, or the like may be placed upon the handle topoint to thescale. In the operation of this invention, assuming eachsparkplug to be constructed as shown in Fig. 1, Fig. 2 and Fig. 3, it isbelieved tobe made out .by the foregoing description that when themovable electrode is turned by the handle E, its bent end D will rubagainst the end of the stationary electrode a, and this may be doneasutiicient number of times to fully clear the electrodes of 'carbondeposit. It is also believed to be apparent that the movement of theelecindicator e overthe scale F, and the distance of one electrode fromthe other may be determined by considering the position of the indicatorwith respect to the scale F. When there are more than one. sparkplug,

- and the devices shown in Fig. 4 are employed, the spark gap isindicated upon the scale P, and, the handle M being placed as desired tosuitably separate the electrodes of tact with the scale P.

the plugs, its position may be fixed by turning the screw-threadedhandpiece into con- Where a number of plugs are used and the movableelectrodes thereof are operated together, it is necessary for theoperator to know the extent of the sparkgaps with certainty, and he mustbe able to secure the parts firmly after adjustment. The position of thehandle M upon scale P plainly indicates the size of the spark-gaps, andby screwing up the handpiece 'N firmly, the sparkgaps cannot be variedby the vibrations of the engine or movements of the vehicle. A number ofchanges in the precise construction and arrangement of the partsillustrated would naturally suggest themselves to a mechanieian familiarwith electrical ignition systems and devices, and itis not intended to11:11- rowly confine this invention to the forms and members as setforth.

Having now described this invention, and explained the mode of itsoperation, what I claim is 1. In adjustable electrode sparkplugs,thecombination with a series of sparkplugs each having a freely movableelectrode by the movement of which the sparking distance between theends of the electrodes may be'varied, of means connected with the said 5movable electrodes of all the sparkplugs for moving said electrodesthereby adjusting the spark gaps between the ends of the electrodes froma distance, a scale arranged at a distance from the said sparkplugs, amem: ber connected with the said electrodes-adjusting means and arrangedto sweep the said scale, and releasable means for securing the-member atany point upon the scale thereby holding the said electrodes-adjustingmeans in a desired position.

2. In adjustable electrode sparkplugs, the combination with a series ofsparkplugs. each having a freely movable electrode by the movement ofwhich the sparking distancebetween the electrodes may be varied, meansconnected with the said movable elec-v trodes of all the sparkplugs formoving the said electrodes thereby adjusting the spark gaps between theends of the electrodes from a.,distance, devices arranged at a distancehaving a passage extending lengthwise 1 30 through its wall and havingits lower por- Ward or from the lower end of the stationtionformed tofit the said conical gas check, my electrode, and means locatedexteriorly the said movable electrode occupying the and connected withthe top of the movable 10 said passa e and being arranged to turn onelectrode for turning the electrode and for 5 its own axls therein, thesaid electrode havsecuring the same in any position.

ing a lower end below the said gas check In testimony whereof I afiix mysignature. constructed to be moved horizontally to- DANIEL M. CLARK.

